According to Wikileaks' hacking of Stratfor Intelligence, the Reverend Jesse Jackson had received a handsome six figure "donation" to, as quoted by WND, "keep his mouth shut".

From the Examiner:

the Democratic Party paid Jessie Jackson six figures to keep his mouth shut about political issues during the 2008 campaign. It was widely known at the time that Jackson had no use for Obama.
The constant meme we hear is that Jackson is not very fond of Obama. But he defended Obama as a "food stamp president" in a speech last week.